The present invention relates to an electronic voting system in which voting is electronically performed by a voting apparatus using a ballot card issued by an accepting apparatus and, more particularly, to an electronic voting system having a function of preventing unauthorized use of the ballot card, a method of preventing such unauthorized use, and a recording medium storing a program.
Currently, voting in an election or the like is generally performed in the following manner. A front desk and ballot box are prepared in a polling place. In the polling place, a ballot sheet is handed to a person who has properly completed an acceptance procedure. The person then writes, on the ballot sheet, the name of a candidate for whom the person wants to vote, and casts the ballot sheet into the ballot box.
Likewise, in a polling place where acceptance and voting procedures are separately performed, a ballot card is issued, instead of a ballot sheet, to a person who has properly completed an acceptance procedure. An electronic voting system designed to perform electronic voting using such ballot cards has been proposed (see, e.g., Japanese Patent Laid-Open No. 6-251048).
The following problems, however, arise in such a conventional electronic voting system.
Assume that in the conventional electronic voting system, after a ballot card is issued to a person, the person carries it out of the polling place without voting, and hands it to the third person. In this case, if the third person enters the polling place upon properly completing an acceptance procedure, he/she can perform voting twice using his/her own ballot card and the ballot card obtained from the above person. This leads to the purchase of votes.
In addition, if voting cannot be done because of a faulty ballot card, a ballot card is reissued. In spite of fact that voting has been completed by inserting a ballot card into the voting apparatus, some person may intentionally break the ballot card and claim that he/she could not cast a vote. However, it is impossible to discriminate them.
The technique disclosed in Japanese Patent Laid-Open No. 6-251048 is based on the premise that an election administration terminal having an eligible voter database storing election information about electors including voting state information indicating an unfinished voting/finished voting state is connected, through a communication line such as a LAN, to an accepting terminal which performs an acceptance procedure by checking this eligible voter database. This reference discloses no arrangement for a case wherein an accepting apparatus designed to perform an acceptance procedure for voting is not connected to a voting apparatus designed to perform voting.